FIG 8.

Excystment assays. Cysts were produced by the inoculation of Vermamoeba vermiformis trophozoites with Faustovirus mariensis at MOIs of 0.01, 0.1, 1, and 10, and then their excystment potential was evaluated. (A) Agar plate excystment assay demonstrating that few cysts obtained from infections at MOIs of 0.01 and 0.1 were able to become trophozoites (arrows). Excystment was not observed for cysts obtained from infections at MOIs of 1 and 10. (B) Viability of cysts produced from infections at different MOIs (trypan blue, 0.4%). Error bars indicate SDs. (C) Transmission electron microscopy representative image demonstrating that only uninfected cysts are able to excyst. This image corresponds to cysts obtained from infections at an MOI of 0.01, after excystment stimulus. (D and E) Cysts produced after infection can present either a regular shape (D) or reduced diameters and irregular shapes (E). These experiments were performed three times in triplicate.